We recently ran into an issue with debug/development mode when making z3c.hashedresource work with Zope2: The package implements different behaviour depending on whether the dev-mode feature is enabled in the ZCML of a Zope3 application, and we sort of expected this feature to be automatically enabled or disabled in a Zope2 application using Five when Zope2 debug-mode is switched on or off, resp. As this doesn't seem to be the case, we were wondering a few things: - Is Zope2 debug mode semantically equivalent to ZCML dev-mode, i.e. should the two be linked to each other in the first place? - If so, is it a bug that ZCML dev-mode isn't controlled by Zope2 debug mode in a Five application? Or is it and we're just missing something? - If the the two should be connected but aren't, what's the best way to fix things? Should this be fixed in Five? Otherwise, how to achieve switching on the ZCML dev-mode feature the right way? Independently of these questions, wouldn't it make sense for ZCML to have, in addition to "feature" and "installed", a conditional verb "expression" that allows referencing a Python expression defined in a module whose boolean value to use for deciding the condition? -- Thomas